私たちは親切親切にグルタミンを供給するためのグルコースのFRETプラスミド博士ウーヴェLudewig（ホーエンハイム大学）をご提供するために教授ウルフフロン（科学カーネギー研究所、スタンフォード大学）に感謝pUTKan植物発現ベクターに構築FRET。 ABはBBSRC目標と重点Studentshipsプログラムによって資金を供給される。 CKとKPの両方がバイオ医薬品の処理にRCUKフェローシップでサポートされています。 CKはまた彼らの財政支援のためにロンザ生物製剤に感謝したい。合成生物学とイノベーションのためのセンターは、寛大にEPSRCによってサポートされています。

1。細胞株リバイバルとメンテナンス<ol><li> 8mMのL-グルタミンおよび10ml / L 100×ヒポキサン​​チン/チミジンサプリメント（完全増殖培地）を補充9ミリリットルCD-CHO培地中でCHO細胞を復活させる。 </li><li> 5分間100×gで遠心分離する。 </li><li>新鮮な完全増殖培地10mlに細胞を再懸濁。 </li><li> 1ミリリットルのサンプルを取り出して、血球計数器でパンブルー色素排除法を用いて光学顕微鏡により生細胞濃度を決定する。 </li><li> 125ミリリットル中に3×10 5細胞/ mlの播種密度で培養を開始するには、振盪フラスコ。 </li><li> 120 rpmで回転する軌道揺れプラットフォーム上で、37℃、5％CO 2の加湿雰囲気のインキュベーター内の文化を維持している。 </li><li> 2×10 5細胞/ mlの播種密度で完全増殖培地中で3〜4日ごとに継代培養する。 </li></ol> 2。プラスミドとC細胞株のトランスフェクションバイオセンサー遺伝子をontaining <ol><li>大規模プラスミド精製キットを用いてプラスミドDNAを調製する。 </li><li>細胞が活発にトランスフェクションの際に分裂していることを確認するために、適切な条件（37℃、5％CO 2）トランスフェクション前に12から24時間で細胞を維持する。 </li><li>トリパンブルー色素排除法を用いて細胞をカウントし、次いで、1×10 6細胞/ mlの濃度で振盪フラスコ中で125ミリリットルの細胞培養物を20mlの作業容量を準備する。 </li><li>使用中の細胞株について適切なトランスフェクションキットを使用してください。トランスフェクション試薬の比のプラスミドDNAは、細胞株およびベクターに依存するであろう。これは、この前の最終のトランスフェクションを実施し、製造業者によって指定された範囲内の比率の範囲をテストすることによって最適化されていることをお勧めします。また、少なくとも1つの負の対照細胞を含有する培養限定なしDNAを維持する。 </li><li>静的モードで4日間インキュベートした後、シャキに転送NGプラットフォームは、125 rpmで回転する。 </li><li>キル曲線によって決定された適当な濃度にプラスミド選択のための適切な抗生物質を追加します。本研究では、ゼオシンをトランスフェクトされた細胞の選択のための400μg/ mlの終濃度に添加した。 </li><li>対照ウェル中の細胞が死ぬまでは、抗生物質のたびに追加し、細胞株のための適切な時間間隔でメディアを変更。 </li><li>文化を振っに進行することが最もコンフルエント井戸を使用してください。 </li><li>凍結混合物1ml中10 7生存細胞を含有するクライオバイアル中に細胞を凍結することにより細胞バンクを確立する。この研究では、これは92.5％の増殖培地および7.5％ジメチルスルホキシドからなる。 </li></ol> 3。バッチおよび流加細胞の成長曲線<ol><li> 50ミリリットルの作業容量で振盪フラスコ250ミリリットル中のトランスフェクトされたCHO細胞の三連細胞培養を確立するために、上記の細胞の維持のための指示に従ってください。 </li><li> cultuを維持125 rpmで回転する軌道揺れプラットフォーム上でのCO 2 5％で37℃、の加湿細胞インキュベーターでRES、および24時間の間隔で、各成長培養物から4.1ミリリットルのサンプルを削除します。 </li><li>トリパンブルー色素排除法で生細胞濃度と細胞生存率を測定するために試料100μlを使用してください。 </li><li>生細胞濃度がゼロになるまで繰り返します。 </li><li>流加細胞培養は、それぞれ、36及び4mmの初期値にそれらの濃度を回復するために、6日目にグルコースまたはグルタミンの適切な量の補給のために繰り返します。なお、純水の同じ体積（ここでは12ml）で供給されるべき、追加の対照培養もまた維持されることが推奨される。 </li></ol> 4。比測定をFRET <ol><li> 4℃で5分間100×gで、上記のステップ3.2および遠心機で取り除か毎日サンプルの2ミリリットルを取る</li><li> Resusp氷冷リン酸緩衝生理食塩水（PBS）2ml中の細胞ペレットを終えた。 6穴プレートにこれを転送し、1ウェルに細胞を含まないブランクサンプルを追加します。 </li><li>すぐに435分の465ナノメートル（青）と510分の520ナノメートル（黄色）の435分の430 nmの波長と発光波長の励起波長で、青と黄色の蛍光のレベルを測定する。 </li><li> FRET比（検出された青色蛍光にわたって検出黄色の蛍光の比率）を計算します。 </li></ol> 5。代謝物アッセイ<ol><li> 4℃で5分間100×gで、上記のステップ3.2および遠心機で取り除か毎日サンプルの2ミリリットルを取る上清を取り除きます。 </li><li> 5分間100×gで再び3ミリリットルの氷冷PBSと遠心機で細胞ペレットを再懸濁します。 </li><li>上清を除去し、上記のように3ミリリットルの氷冷PBSで細胞ペレットを再懸濁します。 15秒、15秒オフのパルスで3分間ずつのサンプル5Xを超音波処理。この時点で、余分な細胞必要に応じて、CTSは凍結することができる。 </li><li> （材料の表を参照）、細胞内のグルコース濃度を決定するために、細胞抽出物試料について、製造業者の指示に従って、適切なグルコースアッセイキットを使用する。 注：標準曲線を構築するために適切な基準を使用してください。本研究では、基準の濃度は0〜100 mMの範囲であった。 </li><li>規格の測定値を使用して、標準曲線を構築し（この場合：yは1310.51x - yは吸光度の読み取りであり、xはグルコース濃度であり723.43）最良適合の直線式を見つける。 </li><li>標準曲線を使用して、アカウントへの希釈を取ってグルコース濃度を計算します。細胞内のグルコース濃度は、この式を用いて計算することができる。 <img alt="" fo:content-width="4.5in" src="/files/ftp_upload/51200/book_bg.png" width="500" /> CHO細胞については、単一細胞体積は、12μM12の気泡径を算出した</SUP&gt;。 </li><li> （材料の表を参照）、細胞内グルタミン濃度を決定するために、細胞抽出物試料について、製造業者の指示に従って適切なグルタミンアッセイキットを使用する。 注：標準曲線を構築するために適切な基準を使用してください。本研究では、基準の濃度は0〜2 mMの範囲であった。 </li><li>上記5.5のように、検量線（この場合はy = 203.1x + yは吸光度の読み取りであり、xはグルコース濃度である17.1）を構築</li><li>標準曲線を用いて、希釈を考慮に入れて、サンプルのグルタミン濃度を算出する。細胞内グルタミン濃度は、上記の式1を用いて計算することができる。 </li></ol>

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著者らは、開示することは何もありません。

FIBS焼入れおよび抽出方法に起因する不確実性を取り除く、この場合、増殖制限栄養素で、 生体内で 、キー分子のその場での定量に有効。知見はFIBS信号及びグルタミングルコースおよび0.3-2 mMの1-5 100mMの範囲で細胞内濃度との間に良好な相関関係があることを示唆している。バッチCHO細胞培養において、これらの濃度は、指数関数、固定、および早期衰退段階で遭遇する...

代謝産物監視は、プロセス開発、メディアおよび飼料設計、および代謝工学などのバイオプロセスにおける様々な用途を有する。種々の方法は、酵素1、化学2、又は3結合アッセイの使用を介して濃度測定に利用可能である。興味深いオプションは、タンパク質ベースのキー代謝物の細胞内濃度のレポーターとして、生体内の生物学的センサーでは 、蛍光の使用である。小型化は、実際に信号対雑音比の4,5を改善し、タンパク質ベースのセンサは、遺伝的に外因性試薬は代謝産物分析のために必要ではないという意味を符号化することができるように、超低容量アッセイにおいて、蛍光は便利なツールである。フェルスター共鳴エネルギー移動（FRET）バイオセンサーは、リガンド結合ドメインによって接続された2つの蛍光タンパク質からなる。 FRETは、アクセプター蛍光分子LOCATへの光励起ドナーからのエネルギーの非放射伝達で<html>すぐ近く（&lt;100）で編。リガンドまたは結合開裂は、順番に、発光スペクトルの変化によって測定されたFRET効率の変化をもたらす、フルオロフォアの近接性の変化を誘導し、センサのコンフォメーション変化を引き起こす。 FRET統合生物学的センサー（FIBSは）構成的に細胞株内で生産され、それらのスペクトル特性は、細胞内の代謝物質の濃度に基づいて変化する。 FIBSは動的モデル6用の測定を行うために最適です迅速な応答時間を有する。以前のアプリケーションでは、7月9日 、単一および複数の10代謝物をモニターし、時空間分布11上のデータを提供することを含む。リガンド結合は、エネルギー移動およびリガンド結合がより密着します（ 図1）に2発蛍光をもたらしたApo-ミンを下げるフルオロフォアの近接性を崩壊させるのApo-マックス、：FIBSは2つの構成で作成することができます。 本研究では_contentは&quot;&gt;、プロトコルはチャイニーズハムスター卵巣構成的代謝産物、グルコースまたはグルタミンFIBSを発現（CHO）細胞株を構築するために提示されている。方法論は、将来の定量を可能にするために、インビボでセンサの較正のために確立されている図2に示すように、細胞内代謝物濃度の測定を、これに基づいて、グルコースまたはグルタミンの細胞内濃度二つの栄養素をインプロセスで高濃度で添加したものに、流加培養CHO細胞培養物で決定することができる。結果それは非侵襲的で低コストであるため、独立した酵素アッセイによって確認されるようにFIBS、予め作成した検量線からの蛍光信号を用いて、細胞内濃度を正確に予測が可能であることを実証している。このメソッドは、現在の分析技術に対する実質的な利点を提供する共通とすることができるFIBSのリアルタイム信号を与えて、高速文化を通じてitored。

<table border="0" cellpadding="0" cellspacing="0" width="936">
	<colgroup>
		<col />
		<col span="2" />
		<col />
	</colgroup>
	<tbody>
		<tr height="22">
			<td height="22" style="height:22px;width:239px;">CHO-S Cells</td>
			<td style="width:120px;">Life Tecnologies</td>
			<td style="width:120px;">11619-012</td>
			<td style="width:459px;">Cell line will vary depending on the goals of the study</td>
		</tr>
		<tr height="22">
			<td height="22" style="height:22px;width:239px;">pCDNA4/TO vector&#160;</td>
			<td style="width:120px;">Life Tecnologies</td>
			<td style="width:120px;"></td>
			<td style="width:459px;"></td>
		</tr>
		<tr height="43">
			<td height="43" style="height:43px;width:239px;">TransIT-PRO Transfection Reagent</td>
			<td style="width:120px;">Mirus Bio</td>
			<td style="width:120px;">MIR 5700</td>
			<td style="width:459px;">Transfections can be accomplished using any method suitable for the cell line under study</td>
		</tr>
		<tr height="22">
			<td height="22" style="height:22px;width:239px;">Zeocin</td>
			<td style="width:120px;">Invivogen</td>
			<td style="width:120px;"></td>
			<td style="width:459px;"></td>
		</tr>
		<tr height="43">
			<td height="43" style="height:43px;width:239px;">CD-CHO medium</td>
			<td style="width:120px;">Life Technologies</td>
			<td style="width:120px;">10743-011</td>
			<td style="width:459px;">Cell growth medium is dependent upon the cells under study</td>
		</tr>
		<tr height="43">
			<td height="43" style="height:43px;width:239px;">100X HT Supplement</td>
			<td style="width:120px;">Life Technologies</td>
			<td style="width:120px;">11067-030</td>
			<td style="width:459px;"></td>
		</tr>
		<tr height="43">
			<td height="43" style="height:43px;width:239px;">L-Glutamine 200 mM (100X), Liquid</td>
			<td style="width:120px;">Life Technologies</td>
			<td style="width:120px;">25030032</td>
			<td style="width:459px;"></td>
		</tr>
		<tr height="43">
			<td height="43" style="height:43px;width:239px;">InfinitePRO 200 plate reader</td>
			<td style="width:120px;">Tecan</td>
			<td style="width:120px;">FLx800TBI</td>
			<td style="width:459px;">Any 96-well fluorescence plate reader that can access the required wavelengths can be substituted</td>
		</tr>
		<tr height="21">
			<td height="190" rowspan="6" style="height:190px;width:239px;">Filters for plate reader</td>
			<td rowspan="6" style="width:120px;">Tecan</td>
			<td align="right" style="width:120px;">30000463</td>
			<td rowspan="6" style="width:459px;"></td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:120px;">(520NM BW 10NM)</td>
		</tr>
		<tr height="21">
			<td align="right" height="21" style="height:21px;width:120px;">30022786</td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:120px;">(430NM BW 35NM)</td>
		</tr>
		<tr height="21">
			<td align="right" height="21" style="height:21px;width:120px;">30022787</td>
		</tr>
		<tr height="43">
			<td height="43" style="height:43px;width:120px;">(465NM BW 35NM)</td>
		</tr>
		<tr height="22">
			<td height="22" style="height:22px;width:239px;">Maxiprep Plasmid Purification Kit</td>
			<td style="width:120px;">Qiagen</td>
			<td style="width:120px;">12163</td>
			<td style="width:459px;">Any suitable kit can be substituted</td>
		</tr>
		<tr height="43">
			<td height="43" style="height:43px;width:239px;">Amplex Red glucose/glucose oxidase assay kit</td>
			<td style="width:120px;">Invitrogen</td>
			<td style="width:120px;">A22189</td>
			<td style="width:459px;">Any suitable kit can be substituted</td>
		</tr>
		<tr height="43">
			<td height="43" style="height:43px;width:239px;">EnzyChrom&#160; Glutamine Assay Kit</td>
			<td style="width:120px;">BioAssay systems</td>
			<td style="width:120px;">EOAC-100</td>
			<td style="width:459px;">Any suitable kit can be substituted</td>
		</tr>
		<tr height="43">
			<td height="43" style="height:43px;width:239px;">Improved Neubauer haemocytometer</td>
			<td style="width:120px;">Fisher Scientific</td>
			<td style="width:120px;">MNK-420-010N</td>
			<td style="width:459px;"></td>
		</tr>
		<tr height="22">
			<td height="22" style="height:22px;width:239px;">Incubator&#160;</td>
			<td style="width:120px;">Nuaire</td>
			<td style="width:120px;">NU-5510E</td>
			<td style="width:459px;"></td>
		</tr>
	</tbody>
</table>

fibs-enabled noninvasive metabolic profiling

計算生物学の時代に、新しい高スループット実験系では、彼らは、予測の目的のために検証できるようにしたモデルを投入し、改良するために必要である。経時データを取得する場合に、理想的にはそのようなシステムは、破壊的サンプリングおよび分析を妨げる低容積、であろう。必要とされるのは、リアルタイムでかつ非侵襲的に必要な情報を報告することができ、その場で監視ツールである。興味深いオプションは、タンパク質ベースの細胞内濃度のレポーターとして、生体内の生物学的センサーでは 、蛍光の使用である。代謝産物の定量化における用途を発見したin vivoでのバイオセンサーの一つの特定のクラスは、リガンド結合ドメインによって接続された2つの蛍光タンパク質間のフェルスター共鳴エネルギー移動（FRET）に基づくものである。統合された生物学的センサー（FIBS）をFRETが構成的に細胞株内で生成され、それらは、速い応答時間およびそのスペクトルを有する茶細胞内の代謝物質の濃度に基づいて変更racteristics。本論文では、細胞内の代謝産物濃度の将来の定量化を可能にするために、構成的にグルコースおよびグルタミンFIBSを発現（CHO）細胞株、チャイニーズハムスター卵巣を構築し、バッチ細胞培養におけるin vivoでの FIBSを較正するための方法が記載されている。フェドバッチCHO細胞培養からのデータはFIBSは細胞内濃度の結果として生じる変化を検出する各々の場合にできたことを示している。独立した酵素アッセイによって確認されるようにFIBS、予め作成した検量線からの蛍光シグナルを用いて、細胞内の濃度を正確に決定した。

方法論の概要を図2に示す。本明細書に提示される研究では、CHO細胞をFIBSベクターおよび安定な細胞株にトランスフェクトした400μg/ mlのゼオシン抗生物質の圧力で選択した。構成的にグルコースおよびグルタミンのセンサーを発現する二つの別々の安定な細胞株は、従って作成された。 図1は、本研究で使用される2つのバイオセンサーの構成を示す図である。グルコ...

Watch this Scientific Journal Video about FIBS-enabled Noninvasive Metabolic Profiling at JoVE.com

FIBS-enabled Noninvasive Metabolic Profiling

その場代謝プロファイリングで用フェルスター共鳴エネルギー移動統合生物学的センサー（FIBS）を校正する方法の説明が提示されている。 FIBSは、非侵襲的に代謝モデルおよびバイオプロセス条件のハイスループットスクリーニングの開発を補助する代謝物の細胞内レベルを測定するために使用することができる。

FIBS対応の非侵襲メタボリック·プロファイリング

In the era of computational biology, new high throughput experimental systems are necessary in order to populate and refine models so that they can be ...

fibs-enabled-noninvasive-metabolic-profiling

Research

JoVE Journal

Bioengineering

9.6K ビュー.  Imperial College London.  その場代謝プロファイリングで用フェルスター共鳴エネルギー移動統合生物学的センサー（FIBS）を校正する方法の説明が提示されている。 FIBSは、非侵襲的に代謝モデルおよびバイオプロセス条件のハイスループットスクリーニングの開発を補助する代謝物の細胞内レベルを測定するために使用することができる。 

ビデオ: FIBS-enabled Noninvasive Metabolic Profiling

High Throughput MicroRNA Profiling: Optimized Multiplex qRT-PCR at Nanoliter Scale on the Fluidigm Dynamic ArrayTM IFCs

The broad involvement of miRNAs in critical processes underlying development, tissue homoeostasis and disease has led to a surging interest among the research and pharmaceutical communities. To study miRNAs, it is essential that the quantification of microRNA levels is accurate and robust. By comparing wild-type to small RNA deficient mouse embryonic stem cells (mESC), we revealed a lack of accuracy and robustness in previous published multiplex qRT-PCR techniques. Here, we describe an optimized method, including purifying away excessive primers from previous multiplex steps before singleplex real time detection, which dramatically increases the accuracy and robustness of the technique. Furthermore, we explain how performing the technique on a microfluidic chip at nanoliter volumes significantly reduces reagent costs and permits time effective high throughput miRNA expression profiling.

Here we describe an optimized multiplex reverse transcriptase quantitative PCR (qRT-PCR) protocol in combination with a microfluidic platform as a cost and time effective high-throughput screening tool for microRNA (miRNA) expression levels, especially when working with limited amounts of sample.

ハイスループットマイクロRNAプロファイリング：最適化されたマルチプレックスフリューダイナミックArrayTMのIFCSでナノリッタースケールでの定量RT - PCR

The broad involvement of miRNAs in critical processes underlying development, tissue homoeostasis and disease has led to a surging interest among the ...

生物工学

In situ Compressive Loading and Correlative Noninvasive Imaging of the Bone-periodontal Ligament-tooth Fibrous Joint

This study demonstrates a novel biomechanics testing protocol. The advantage of this protocol includes the use of an in situ loading device coupled to a high resolution X-ray microscope, thus enabling visualization of internal structural elements under simulated physiological loads and wet conditions. Experimental specimens will include intact bone-periodontal ligament (PDL)-tooth fibrous joints. Results will illustrate three important features of the protocol as they can be applied to organ level biomechanics: 1) reactionary force vs. displacement: tooth displacement within the alveolar socket and its reactionary response to loading, 2) three-dimensional (3D) spatial configuration and morphometrics: geometric relationship of the tooth with the alveolar socket, and 3) changes in readouts 1 and 2 due to a change in loading axis, i.e. from concentric to eccentric loads. Efficacy of the proposed protocol will be evaluated by coupling mechanical testing readouts to 3D morphometrics and overall biomechanics of the joint. In addition, this technique will emphasize on the need to equilibrate experimental conditions, specifically reactionary loads prior to acquiring tomograms of fibrous joints. It should be noted that the proposed protocol is limited to testing specimens under ex vivo conditions, and that use of contrast agents to visualize soft tissue mechanical response could lead to erroneous conclusions about tissue and organ-level biomechanics.

In situ Compressive Loading and Correlative Noninvasive Imaging of the Bone-periodontal Ligament-tooth Fibrous Joint

In this study, the use of an in situ loading device coupled with micro-X-ray computed tomography for fibrous joint biomechanics will be discussed. Experimental readouts identifiable with an overall change in joint biomechanics will include: 1) reactionary force vs. displacement, i.e. tooth displacement within the alveolar socket and its reactionary response to loading, 2) three-dimensional (3D) spatial configuration and morphometrics, i.e.&#160;geometric relationship of the tooth with the alveolar socket, and 3) changes in readouts 1 and 2 due to a change in loading axis, i.e. concentric or eccentric loads.

その場圧縮負荷と骨歯根膜歯繊維状合同の相関的非侵襲的イメージングで

This study demonstrates a novel biomechanics testing protocol. The advantage of this protocol includes the use of an in situ loading device coupled to a ...

Quantification and Size-profiling of Extracellular Vesicles Using Tunable Resistive Pulse Sensing

Extracellular vesicles (EVs), including &#8216;microvesicles&#8217; and &#8216;exosomes&#8217;, are highly abundant in bodily fluids. Recent years have witnessed a tremendous increase in interest in EVs. EVs have been shown to play important roles in various physiological and pathological processes, including coagulation, immune responses, and cancer. In addition, EVs have potential as therapeutic agents, for instance as drug delivery vehicles or as regenerative medicine. Because of their small size (50 to 1,000 nm) accurate quantification and size profiling of EVs is technically challenging.
This protocol describes how tunable resistive pulse sensing (tRPS) technology, using the qNano system, can be used to determine the concentration and size of EVs. The method, which relies on the detection of EVs upon their transfer through a nano sized pore, is relatively fast, suffices the use of small sample volumes and does not require the purification and concentration of EVs. Next to the regular operation protocol an alternative approach is described using samples spiked with polystyrene beads of known size and concentration. This real-time calibration technique can be used to overcome technical hurdles encountered when measuring EVs directly in biological fluids.

Extracellular vesicles play important roles in physiological and pathological processes, including coagulation, immune responses, and cancer or as potential therapeutic agents in drug delivery or regenerative medicine. This protocol presents methods for the quantification and size characterization of isolated and non-isolated extracellular vesicles in various fluids using tunable resistive pulse sensing.

調整可能な抵抗パルスセンシングを使用して定量化し、細胞外小胞の大きさ、プロファイリング

Extracellular vesicles (EVs), including &#8216;microvesicles&#8217; and &#8216;exosomes&#8217;, are highly abundant in bodily fluids. Recent years have ...

Easy and Accurate Mechano-profiling on Micropost Arrays

Cell culture substrates with integrated flexible microposts enable a user to study the mechanical interactions between cells and their immediate surroundings. Particularly, cell-substrate interactions are the main interest. Today micropost arrays are a well-characterized and established method with a broad range of applications that have been published over the last decade. However, there seems to be a reservation among biologists to adapt the technique due to the lengthy and challenging process of micropost manufacture along with the lack of easily approachable software for analyzing images of cells interacting with microposts. 
The force read-out from microposts is surprisingly easy. A micropost acts like a spring with the cell ideally attached at its tip. Depending on size a cell applies force from its cytoskeleton through one or multiple focal adhesion points to the micropost, thus deflecting the micropost. The amount of deflection correlates directly to the applied force in direction and in magnitude. The number of microposts covered by a cell and the post deflection patterns are characteristic and allow determination of values like force per post and many biologically relevant parameters that allow &#8220;mechano-profiling&#8221; of cell phenotypes.
A convenient method for mechano-profiling is described here combining the first generation of ready-to-use commercially available microposts with an in-house developed software package that is now accessible to all researchers. As a demonstration of typical application, single images of bone cancer cells were taken in bright-field microscopy for mechano-profiling of cell line models of metastasis. This combination of commercial traction force sensors and open source software for analysis allows for the first time a rapid implementation of the micropost array technique into routine lab work done by non-expert users. Furthermore, a robust and streamlined analysis process enables a user to analyze a large number of micropost images in a highly time-efficient manner.

Described are protocols for quantifying mechanical interactions between adherent cells and microstructured substrates. These interactions are closely linked to essential cell behaviors including migration, proliferation, differentiation, and apoptosis. The protocols present an open-source image analysis software called MechProfiler, which enables determination of involved forces for each micropost.

マイクロポストアレイ上の簡単かつ正確なメカノプロファイリング

Cell culture substrates with integrated flexible microposts enable a user to study the mechanical interactions between cells and their immediate ...

Metabolic Glycoengineering of Sialic Acid Using N-acyl-modified Mannosamines

Sialic acid (Sia) is a highly important constituent of glycoconjugates, such as N- and O-glycans or glycolipids. Due to its position at the non-reducing termini of oligo- and polysaccharides, as well as its unique chemical characteristics, sialic acid is involved in a multitude of different receptor-ligand interactions. By modifying the expression of sialic acid on the cell surface, sialic acid-dependent interactions will consequently be influenced. This can be helpful to investigate sialic acid-dependent interactions and has the potential to influence certain diseases in a beneficial way. Via metabolic glycoengineering (MGE), the expression of sialic acid on the cell surface can be modulated. Herein, cells, tissues, or even entire animals are treated with C2-modified derivatives of N-acetylmannosamine (ManNAc). These amino sugars act as sialic acid precursor molecules and therefore are metabolized to the corresponding sialic acid species and expressed on glycoconjugates. Applying this method produces intriguing effects on various biological processes. For example, it can drastically reduce&#160;the expression of polysialic acid (polySia) in treated neuronal cells and thus affects neuronal growth and differentiation. Here, we show the chemical synthesis of two of the most common C2-modified N-acylmannosamine derivatives, N-propionylmannosamine (ManNProp) as well as N-butanoylmannosamine (ManNBut), and further show how these non-natural amino sugars can be applied in cell culture experiments. The expression of modified sialic acid species is quantified by high performance liquid chromatography (HPLC) and further analyzed via mass spectrometry. The effects on polysialic acid expression are elucidated via Western blot using a commercially available polysialic acid antibody.

Metabolic Glycoengineering of Sialic Acid Using N-acyl-modified Mannosamines

Sialic acid is a typical monosaccharide-unit found in glycoconjugates. It is involved in a plethora of molecular and cellular interactions. Here we present a method to modify cell surface sialic acid expression using metabolic glycoengineering with N-acetylmannosamine derivatives.

Nを用いたシアル酸の代謝独自-アシル-Mannosamines を変更

Sialic acid (Sia) is a highly important constituent of glycoconjugates, such as N- and O-glycans or glycolipids. Due to its position at the non-reducing ...

Metabolic Support of Excised, Living Brain Tissues During Magnetic Resonance Microscopy Acquisition

This protocol describes the procedures necessary to support normal metabolic functions of acute brain slice preparations during the collection of magnetic resonance (MR) microscopy data. While it is possible to perform MR collections on living, excised mammalian tissue, such experiments have traditionally been constrained by resolution limits and are thus incapable of visualizing tissue microstructure. Conversely, MR protocols that did achieve microscopic image resolution required the use of fixed samples to accommodate the need for static, unchanging conditions over lengthy scan times. The current protocol describes the first available MR technique that enables imaging of living, mammalian tissue samples at microscopic resolutions. Such data is of great importance to the understanding of how pathology-based contrast changes occurring at the microscopic level influence the content of macroscopic MR scans such as those used in the clinic. Once such an understanding is realized, diagnostic methods with greater sensitivity and accuracy can be developed, which will translate directly to earlier disease treatment, more accurate therapy monitoring and improved patient outcomes.
While the described methodology focuses on brain slice preparations, the protocol is adaptable to any excised tissue slice given that changes are made to the gas and perfusate preparations to accommodate the tissue&#39;s specific metabolic needs. Successful execution of the protocol should result in living, acute slice preparations that exhibit MR diffusion signal stability for periods up to 15.5 h. The primary advantages of the current system over other MR compatible perfusion apparatuses are its compatibility with the MR microscopy hardware required to attain higher resolution images and ability to provide constant, uninterrupted flow with carefully regulated perfusate conditions. Reduced sample throughput is a consideration with this design as only one tissue slice may be imaged at a time.

The current protocol describes a method by which users can maintain viability of acute hippocampal and cortical slice preparations during the collection of magnetic resonance microscopy data.

代謝サポートの切除、生体脳磁気共鳴顕微鏡集録時に

This protocol describes the procedures necessary to support normal metabolic functions of acute brain slice preparations during the collection of magnetic ...

Calorespirometry: A Powerful, Noninvasive Approach to Investigate Cellular Energy Metabolism

Many cell lines used in basic biological and biomedical research maintain energy homeostasis through a combination of both aerobic and anaerobic respiration. However, the extent to which both pathways contribute to the landscape of cellular energy production is consistently overlooked. Transformed cells cultured in saturating levels of glucose often show a decreased dependency on oxidative phosphorylation for ATP production, which is compensated by an increase in substrate-level phosphorylation. This shift in metabolic poise allows cells to proliferate despite the presence of mitochondrial toxins. In neglecting the altered metabolic poise of transformed cells, results from a pharmaceutical screening may be misinterpreted since the potentially mitotoxic effects may not be detected using model cell lines cultured in the presence of high glucose concentrations. This protocol describes the pairing of two powerful techniques, respirometry and calorimetry, which allows for the quantitative and noninvasive assessment of both aerobic and anaerobic contributions to cellular ATP production. Both aerobic and anaerobic respirations generate heat, which can be monitored via calorimetry. Meanwhile, measuring the rate of oxygen consumption can assess the extent of aerobic respiration. When both heat dissipation and oxygen consumption are measured simultaneously, the calorespirometric ratio can be determined. The experimentally obtained value can then be compared to the theoretical oxycaloric equivalent and the extent of the anaerobic respiration can be judged. Thus, calorespirometry provides a unique method to analyze a wide range of biological questions, including drug development, microbial growth, and fundamental bioenergetics under both normoxic and hypoxic conditions.

This protocol describes calorespirometry, the direct and simultaneous measurement of both heat dissipation and respiration, which provides a noninvasive approach to assess energy metabolism. This technique is used to assess the contribution of both aerobic and anaerobic pathways to energy utilization by monitoring the total cellular energy flow.

Calorespirometry: 細胞のエネルギー代謝を調査する強力な非侵襲的アプローチ

Many cell lines used in basic biological and biomedical research maintain energy homeostasis through a combination of both aerobic and anaerobic ...

Nanosensors to Detect Protease Activity In Vivo for Noninvasive Diagnostics

Proteases are multi-functional enzymes that specialize in the hydrolysis of peptide-bonds and control broad biological processes including homeostasis and allostasis. Moreover, dysregulated protease activity drives pathogenesis and is a functional biomarker of diseases such as cancer; therefore, the ability to detect protease activity in vivo may provide clinically relevant information for biomedical diagnostics. The goal of this protocol is to create nanosensors that probe for protease activity in vivo by producing a quantifiable signal in urine. These protease nanosensors consist of two components: a nanoparticle and substrate. The nanoparticle functions to increase circulation half-life and substrate delivery to target disease sites. The substrate is a short peptide sequence (6-8 AA), which is designed to be specific to a target protease or group of proteases. The substrate is conjugated to the surface of the nanoparticle and is terminated by a reporter, such as a fluorescent marker, for detection. As dysregulated proteases cleave the peptide substrate, the reporter is filtered into urine for quantification as a biomarker of protease activity. Herein we describe construction of a nanosensor for matrix metalloproteinase 9 (MMP9), which is associated with tumor progression and metastasis, for detection of colorectal cancer in a mouse model.

Nanosensors to Detect Protease Activity In Vivo for Noninvasive Diagnostics

Proteases are tightly regulated enzymes involved in fundamental biological processes, and dysregulated protease activity drives progression of complex diseases such as cancer. This method&#39;s goal is to create nanosensors that measure protease activity in vivo by producing a cleavage signal that is detectable from host urine and discriminates disease.

非侵襲的診断のプロテアーゼ活動In Vivo検出するナノセンサー

Proteases are multi-functional enzymes that specialize in the hydrolysis of peptide-bonds and control broad biological processes including homeostasis and ...

Measuring Global Cellular Matrix Metalloproteinase and Metabolic Activity in 3D Hydrogels

Three-dimensional (3D) cell culture systems often more closely recapitulate in vivo cellular responses and functions than traditional two-dimensional (2D) culture systems. However, measurement of cell function in 3D culture is often more challenging. Many biological assays require retrieval of cellular material which can be difficult in 3D cultures. One way to address this challenge is to develop new materials that enable measurement of cell function within the material. Here, a method is presented for measurement of cellular matrix metalloproteinase (MMP) activity in 3D hydrogels in a 96-well format. In this system, a poly(ethylene glycol) (PEG) hydrogel is functionalized with a fluorogenic MMP cleavable sensor. Cellular MMP activity is proportional to fluorescence intensity and can be measured with a standard microplate reader. Miniaturization of this assay to a 96-well format reduced the time required for experimental set up by 50% and reagent usage by 80% per condition as compared to the previous 24-well version of the assay. This assay is also compatible with other measurements of cellular function. For example, a metabolic activity assay is demonstrated here, which can be conducted simultaneously with MMP activity measurements within the same hydrogel. The assay is demonstrated with human melanoma cells encapsulated across a range of cell seeding densities to determine the appropriate encapsulation density for the working range of the assay. After 24 h of cell encapsulation, MMP and metabolic activity readouts were proportional to cell seeding density. While the assay is demonstrated here with one fluorogenic degradable substrate, the assay and methodology could be adapted for a wide variety of hydrogel systems and other fluorescent sensors. Such an assay provides a practical, efficient and easily accessible 3D culturing platform for a wide variety of applications.

Here, a protocol is presented for encapsulating and culturing cells in poly(ethylene glycol) (PEG) hydrogels functionalized with a fluorogenic matrix metalloproteinase (MMP)-degradable peptide. Cellular MMP and metabolic activity are measured directly from the hydrogel cultures using a standard microplate reader.

世界的な細胞のマトリックスメタロプロテアーゼと 3 D ゲルの代謝活性を測定

Three-dimensional (3D) cell culture systems often more closely recapitulate in vivo cellular responses and functions than traditional two-dimensional (2D) ...

A Human 3D Extracellular Matrix-Adipocyte Culture Model for Studying Matrix-Cell Metabolic Crosstalk

The extracellular matrix (ECM) plays a central role in regulating tissue homeostasis, engaging in crosstalk with cells and regulating multiple aspects of cellular function. The ECM plays a particularly important role in adipose tissue function in obesity, and alterations in adipose tissue ECM deposition and composition are associated with metabolic disease in mice and humans. Tractable in vitro models that permit dissection of the roles of the ECM and cells in contributing to global tissue phenotype are sparse. We describe a novel 3D in vitro model of human ECM-adipocyte culture that permits study of the specific roles of the ECM and adipocytes in regulating adipose tissue metabolic phenotype. Human adipose tissue is decellularized to isolate ECM, which is subsequently repopulated with preadipocytes that are then differentiated within the ECM into mature adipocytes. This method creates ECM-adipocyte constructs that are metabolically active and retain characteristics of the tissues and patients from which they are derived. We have used this system to demonstrate disease-specific ECM-adipocyte crosstalk in human adipose tissue. This culture model provides a tool for dissecting the roles of the ECM and adipocytes in contributing to global adipose tissue metabolic phenotype and permits study of the role of the ECM in regulating adipose tissue homeostasis.

We describe a 3D human extracellular matrix-adipocyte in vitro culture system that permits dissection of the roles of the matrix and adipocytes in contributing to adipose tissue metabolic phenotype.

マトリックス細胞代謝クロストークを研究するためのヒト3D細胞外マトリックス-脂肪細胞培養モデル

The extracellular matrix (ECM) plays a central role in regulating tissue homeostasis, engaging in crosstalk with cells and regulating multiple aspects of ...